This paper introduces a new family of cases where agents are jointly morally responsible for
outcomes over which they have no individual control, a family that resists standard ways of
understanding outcome responsibility. First, the agents in these cases do not individually
facilitate the outcomes and would not seem individually responsible for them if the other
agents were replaced by non-agential causes. This undermines attempts to understand joint
responsibility as overlapping individual responsibility; the responsibility in question is
essentially joint. Second, the agents involved in these cases are not aware of each other's
existence and do not form a social group. This undermines attempts to understand joint
responsibility in terms of actual or possible joint action or joint intentions, or in terms of other
social ties. Instead, it is argued that intuitions about joint responsibility are best understood
given the Explanation Hypothesis, according to which a group of agents are seen as jointly
responsible for outcomes that are suitably explained by their motivational structures:
something bad happened because they didn’t care enough; something good happened because
their dedication was extraordinary. One important consequence of the proposed account is
that responsibility for outcomes of collective action is a deeply normative matter.